code: def get_symbol(self) -> str:
      if self.etype == ExpressionType.COMPARE_EQUAL:
          return "="
      elif self.etype == ExpressionType.COMPARE_GREATER:
          return ">"
      elif self.etype == ExpressionType.COMPARE_LESSER:
          return "<"
      elif self.etype == ExpressionType.COMPARE_GEQ:
          return ">="
      elif self.etype == ExpressionType.COMPARE_LEQ:
          return "<="
      elif self.etype == ExpressionType.COMPARE_NEQ:
          return "!="
      elif self.etype == ExpressionType.COMPARE_CONTAINS:
          return "@>"
      elif self.etype == ExpressionType.COMPARE_IS_CONTAINED:
          return "<@"
  
file_path: evadb/evadb/expression/comparison_expression.py
imports: from evadb.expression.abstract_expression import AbstractExpression, ExpressionReturnType, ExpressionType
  from evadb.models.storage.batch import Batch
label_desc: Use image node_id 3 for calling the ComparisonExpression obj's underlying member method code with example usage: obj.get_symbol() and returns: str, str, str, str, str, str, str, str